First Look: Jaguar C-X75 Concept

September 29, 2010

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By:
Automobile Magazine

In times like these, show cars are no longer mere attention-grabbers. To succeed, concepts need to be design exercises with a message—the greener, the better. The Jaguar C-X75 (concept, experimental, celebrating the brand’s 75th anniversary) meets this description with a refreshingly bold and remarkably different approach.

What we have here is a radically dynamic and amazingly frugal two-seater that employs a pair of micro-turbines acting as diesel-fed range extenders for its battery-powered EV motor. The result combines high-end performance with the kind of fuel economy, emissions, and driving range not even subcompact hybrids can achieve today. In addition, the C-X75 is a true innovator in terms of style, materials, ergonomics and vehicle dynamics. Will it go into production? Probably not. But it does incorporate more elements that are here to stay than most of its comparatively conventional counterparts on the catwalk.

The brief given the project team was to create a “design-led, sustainable high-performance eco-sports car” for the Paris Show. What Jaguar top management did NOT want was a relatively straightforward V-8 hybrid like the Porsche 918, nor an EV like the Mercedes-Benz SLS E-Cell, and certainly not a frugality-through-sacrifice compromise like the Jaguar XJ220, which deserved a V-12 but featured a twin-turbocharged V-6 instead.

Why, we ask, did Jaguar choose micro-turbines, why diesel fuel, why not a pure EV approach like the Audi R8 e-tron or the Mercedes SLS E-Cell? “Because there is such a thing as range anxiety, because the turbines weigh significantly less than the lightest alternative range extender, and because there is no more efficient fuel than diesel,” answers the chief engineer Peter Richings. “You see, the small gas turbines tip the scales at 55 pounds each. In addition, they don’t need oil lubrication or a catalytic converter, and they will run on almost anything from biofuel to LPG. Although they rev at up to 80,000 rpm, turbines are a very reliable known quantity. The fact that they may take up to 15 seconds to reach their optimum operating speed does not really matter here because they are only used to recharge the batteries.”

The silver show car is indeed fitted with the advertised drivetrain, but since the innovative propulsion system is still in its infancy, the car’s moves are positively slo-mo. The noise it makes vaguely resembles a jet airliner. But unlike the turbine-powered prototypes of years ago, the water-cooled turbines used in this application do not drive the wheels. Instead, they charge the batteries while the car is underway. Motive force is provided by four electric motors, each weighing only 110 pounds, which combine to produce 780 hp along with an irresistible 1179 pound-feet of torque. Since the micro-turbines, which deliver 95 hp each, sip from a 16-gallon diesel tank, Jaguar quotes a CO2 emission of only 28g/km. The zero-emission range is a useful 68 miles. To restore the full battery strength, hook up the vehicle to a domestic power line for about five hours.

The air that feeds the turbines is sucked in at sill level from where it circulates through an S-shaped full-height intake chamber. You can see the complete installation from above through a Perspex cover. The four electric motors are mounted close to the wheels and are governed by Jaguar’s own software, which includes fully integrated traction control, stability control and torque vectoring. The adaptive double-wishbone suspension is borrowed from the XKR. Between the axles, embedded in the extruded and bonded aluminum chassis, sits the battery pack which weighs 408 pounds and has a capacity of 15kW. The lithium-ion phosphate energy cells feed four generators and four motors through one single-speed transmission.

Laid over a generous wheelbase of 107 inches, the car is 183 inches long, 80 inches wide and 47 inches high. Enhancing the eye appeal are two swan-wing doors and machined-from-solid, twelve-spoke alloy wheels shod with custom Pirellis (265/30ZR21 in the front, 365/25ZR22 in the rear). The unconventional tread pattern is highlighted by a bright green ribbon, which suggests that even the tires are environmentally friendly.

In the cabin, headroom is scant, but there is plenty of space for spidery legs and wide shoulders.
The TFT instrument panel features two large round gauges, one center color display and an additional side monitor dubbed wingman. It displays detail information such as current and previous lap times, trip and fuel economy data as well as fluid levels and temperatures. The main dials can switch from touring mode (road speed/driving range) over Vmax mode (speed gauge/power gauge) to heritage mode (analogue D-type look). Although range anxiety is not really an issue, the energy depletion rate depends a lot on your driving style, so there are all sorts of bar graphs suggesting to take it easy. Embedded in this space-age fascia is a Bowers & Wilkins sound system boasting 120 lightweight honeycomb miniature speakers covered by polished micromesh panels. Nice. There are three different drive modes to select from: EV, standard, and track. At the moment, they all sound the same, but Jaguar is developing a set of synthetic soundtracks to stimulate the driver while at the same time alerting absent-minded cyclists and pedestrians.

The performance figures are quite simply phenomenal. Jaguar calculates 3.4 seconds for the sprint from 0 to 62 mph, a top speed of 205 mph, and a quarter mile time of 10.3 seconds. While 0-100 mph is allegedly a 5.5-second affair, 0-200 mph is an equally impressive 17.5-second exercise. Bugatti Veyron, this is your worst nightmare coming true. The power to weight ratio is 445 hp per ton; the torque-to-weight figure is an even more outrageous 674 pound-feet per ton. Surely there is an Achilles heel or two to be found in this Guinness Book data.

“Well, maximum speed can only be maintained for about 60 seconds,” admits Peter Richings. “That’s when the electric motors reach their thermo limit. Having said that, it is extremely difficult to find a stretch of track where you can sustain 200-plus mph for longer than one minute.”

So you better back off, although even 180 mph is restricted to 120 seconds because the system is still running at the maximum discharge rate. The fastest steady velocity C-X75 can maintain without doing damage to the soft- or hardware is 138 mph. At this speed, the two turbines are spinning full whack as all the effort is converted into providing energy and none into recharging. You can cruise all day at 100 mph with one jet powering and the other one charging.

So, yes, there are some limitations. But still, this Jaguar does encapsulate the best of both worlds: traditional good looks and fine craftsmanship with fresh proportions, materials and content. Like the old XJ, C-X75 has two prominent filler caps, one for diesel and one for plug-in connector. Like the current XJ, it has multi-mode instruments and a modern demeanor. No wood, but translucent composites. No chrome, but a mix of polished and shot-blast aluminum. No cigar-lounge grandpa leather, but a mix of soft ecru and slate hide complemented by shrink-wrapped neoprene. No display-case V-8 but a theatre-lit blue-and-white polished air chamber dominated by two jewel-like micro-turbines. No wild spoilers but a poster-quality body sporting a drag figure of 0.32cD.

That body, by Ian Callum and his deputy Julian Thompson, is an absolute stunner. While the front is relatively brand-generic, the rear and side views are exactly the stuff automotive design dreams are made of. The interior, too, breaks enough rules to surprise and to move the ergonomic game to the next level.

“A sporty coupe is ideally suited to capture the new spirit of Jaguar,” explains Callum. “This vehicle ticks all the right boxes: it moves our form language to a higher level, it is state-of-the-art in terms of materials used and weight saved, it is refreshingly minimalistic in style and execution, and as far as electrification goes, it offers a variety of fresh and yet quite feasible solutions.”

There is no doubt it: this car is an event, a turning point, a potential pace setter. It has got what it takes to put the brand firmly back in the alternative propulsion race, and it adds a large measure of Britishness to the DNA, which makes clever high-tech green the most desirable color of all.